1. Field of the Invention
The present invention relates to electric power generation devices and systems, mounted on motor vehicles comprised of internal combustion engines, which control a generation of electric power by an alternator driven by an internal combustion engine and a supply of the generated electric power to a battery.
2. Description of the Related Art
There is a known device regarding such a type of the electric power generation control devices. For example, a patent document, Japanese patent No. JP 4483985, has disclosed a device to adjust a driving torque of an alternator to suppress various vibrations of a motor vehicle. In general, various types of vibrations are caused in a motor vehicle, for example, twisting vibration, pitching vibration, vibration of an internal combustion engine, etc. The twisting vibration is caused by twisting a crank shaft and/or a drive shaft of the internal combustion engine mounted to the motor vehicle. The pitching vibration is caused in a pitching direction by a driving force or a brake force.
By the way, in general such an electric power generation control device performs a feedback control of an exciting current flowing in an excitation winding of an alternator by a voltage regulator in order to adjust an electric power generated by the alternator within a predetermined reference voltage. In order to achieve this control, the electric power generation control device disclosed in the patent document No. JP 4483985 adjusts an output current of the alternator by adjusting an exciting current in order to change an amount of generated electric power. However, in order to perform the control of adjusting an exciting current, the conventional electric power generation control device is required to add a specific device.
That is, when a battery having a large electric resistance (charging/discharging resistance), which is generated during electric charging/discharging operation, is mounted to a motor vehicle, it becomes difficult to correctly perform a control of a generation amount of electric power by directly adjusting an output current of the alternator, as previously described, because a charging/discharging resistance is greatly changed according to an amount of a residual capacity (i.e. a residual charge) of the battery. In order to avoid this problem, it is for example necessary to replace the battery with a new battery having a small charging/discharging resistance.